1998 ford explorer ground bias?

Hi everyone.

Costumer complain is lack of power and hesitation when acelerating.

Scanner is telling me both banks are rich all the time and STFT is about 10 to 16%.

O2 voltage oscillating from 0.48 to 1.00 and O2 ground steady at 0.24 volts (both banks). O2 heater about 14 volts on power and 0.4 on ground.

Is it a ground issue or 0.2 volts bias ground?

Thanks in advance.

Thanks Monde,

I have seen a couple of times the video, but i'm afraid i didn't catch the idea.

I don't have any schematics, nor voltage values for this car. So actually I'm trying to look for direction from any of you who have worked specifically in one of this.

If i assume is a ground issue, that drives me to swap pcm or tear it down to realized whether or not O2 ground and PCM ground are decoupled (which is a long way).

If i assume is a bias ground voltage. I can say O2 sensor is oscillating right as it should (from (0.48 - 0.24) to (1.0 - 0.24)). Then i have to look for a new direction.

Actually i don't know whether or not this detail is on wiring diagram.

Regards.

Thanks again Monde,

How about a ground which has "gained" resistance by corrosion or temperature.

Does it light anyway?